Oral pre-exposure prophylaxis (PrEP) has been proven effective in reducing HIV infection in high-risk men who have sex with men, heterosexually active women and men, and injecting drug users. Despite its 2012 approval by the FDA and the development of CDC clinical guidelines, PrEP uptake has been limited. Significant impediments to PrEP implementation include: system barriers (lack of a medical home and of models for implementing PrEP); provider barriers (difficulty identifying those likely to benefit from PrEP, inexperience with PrEP, and concerns about adherence and risk compensation); and user barriers (lack of awareness of PrEP, inability to access providers comfortable with prescribing PrEP, and concerns about stigma and side effects). Cost is not a barrier in New York State, where PrEP is covered by many insurance plans, including Medicaid. Primary Care for PrEP (PC4PrEP) is a structural, multilevel intervention that will integrate PrEP into primary care practices that care for underserved communities in the Bronx, NY, an epicenter of continuing HIV infection in the US. The proposed study is closely aligned with the goals of the Patient Protection and Affordable Care Act in expanding high-quality coordinated primary care in community health centers and integrating HIV/AIDS prevention and treatment services into primary care. PC4PrEP will develop an organizational protocol for prescribing PrEP in primary care; identify high-risk individuals in primary care clinics and community HIV testing sites using a new PrEP Eligibility Tool; link them to primary care providers (PCPs) who can provide PrEP; and counsel potential users about PrEP both before they receive a prescription (to enhance receptivity), and after they initiate PrEP (to enhance adherence). In the course of this study, we will (1) develop and pilot PC4PrEP; (2) implement and evaluate it in real-world settings (Federally Qualified Health Centers; FQHCs) on objective outcomes as well as provider and patient reports; and (3) present a new model, the PrEP Cascade that - as with the HIV Care Cascade for HIV+ populations - may be used to evaluate the impact of PrEP programs in the US and other countries. PC4PrEP is consistent with CDC and NYSDOH Guidelines and the Affordable Care Act in integrating PrEP into primary care practices and is responsive to recent 2014 NYSDOH recommendations which now position PrEP as a first-line intervention for MSM and transgender women who engage in ongoing condomless anal sex, HIV- partners in sero-discordant relationships, and high-risk heterosexual women in high seroprevalence areas. There are two Specific Aims: (1) Finalize the PC4PrEP intervention and, in a clinic-randomized Phase 2 futility trial, assess whether it shows promise for increasing PrEP prescription rates in the Bronx, NY; and (2) Identify strengths and limitations of PC4PrEP in two ways: (a) through a mixed-methods process evaluation PrEP-eligible patients and PCPs, counselors and navigators; and (b) by identifying fall-off at each step of the PrEP Cascade.